Clarification of oil

Crude oil contains a  suspension of fine pulp and fibre from the plant material. It also contains smaller quantities of water, resins, colors and bacteria, which makes it darker in colour. These contaminants are removed by clarifying the oil, either by allowing the oil to stand undisturbed for a few days and then removing the upper layer, or by using a clarifier. If further clarification is needed, the oil may be filtered through a plastic funnel, which has been fitted with a fine filter cloth. Finally, the oil is heated to boil off the traces of water and destroy any bacteria. For those raw materials, which are processed wet (such as coconut), heating is applied prior to clarification in order to  break the emulsion. When these impurities are removed, the shelf-life of the oil can be extended from  a few days to several months, provided it is stored properly.